Method of firing boilers or furnaces by hydrocarbon.



K. M. DAHL. METHOD OF FIRING-BOILERS OR FURNACES BY HYDROGARBON.

APPLICATION FILED SEPT. 14, 1911.

Patented Mar. 11, 1913.

INVENTOR ATTORNEYS UTED STATES KNUT M. DAHL, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR T'O UNION IRON WORKS (10., OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF NEW JERSEY.

MFTHOD OF FIRING BOILERS OR FURNACES BY HYDROCARBON. I

, Specification of Letters Patent.

Application filed September 14, 1911. Serial No. 649,307.

To all whom it may concern:

. Be it known that I, KNUT M. DAHL, acitizen of the United States, residing in the troleum or other oil so that the same may be readily utilized for fuel in a furnace without leaving any residuum, or smoke,one'

form of hydrocarbon to which vmy invention is applicable being the heavy California oils whose base is asphaltic, although my invention is equally adapted to use with the lighter hydrocarbon products. In carrying out my novel method I employ a series of atomizing steps, which comprise projecting a jet or jets of heated hydrocarbon or liquid fuel maintained under pressure and heated to the desired degree angularly and then longitudinally with respect to the direction or flow of the incoming fiuid, then causing the jet or jets to travel inwardly in a direction at substantially a-rightangle to the path of the incoming fluid, whereby the velocity is momentarily checked the fluid is deflected in a state of agitation into a common commingling chamber, the hydrocarbon being thus finely divided andminutely disaggregated and its molecules being next given a swirling or rotary motion and caused to impact against each other and commingle in said common commingling chamber, wherein theflow of fluid is retarded through a contracted outlet port, 'the finely divided molecules of heated hydrocarbon under pressure issuing finally from said contracted port to the point of consumption'in the form of a jet or spray, and

being'commingled'with one or more currents of air' introduced into said spray.

My invention further consists in initially forcing the hydrocarbon through a super-r heating chamber under pressure, heating the said hydrocarbon to a point higher than its normal boiling point, but not sufficiently high to be vaporized if desired, then conducting the heatedoil or hydrocarbon still under pressure and unmixed with air or other gases into the atomizing device, wherein the final steps of my process above recited are carried out, and finally spraying the heated oil under pressure into the combustionchamber' and introducing air through one or more conduits into the hydrocarbon spray, or into the combustion chamber, whereby the vapor which has developed and the small'particles of sprayed hydrocarbon are completely consumed in thecurrent of air that is introduced at the point, of consumption.

My invention further consists of a novel method of atomizing and feeding oil to furnaces, wherein the oil unmixed with air or other -gases is preferably heated to a point higher than its normal boiling point, but preferably not sufiiciently high to be vaporized if desired, said oil being maintained in a compressed, heated and liquid state until it is discharged from the atomizer, after 'havingbeen subjected to the atomizing steps described, into the combustion chamber .of the furnace, said oil during its passage under pressure through the atomizer being given a rotary movement by beingcaused to travel tangentially to the longitudinal'axis of the aperture in the burner tip, and to be'thereafter commingled in a chamber having a restricted outlet, whereby the main element used in the atomization of the oil is the pressure to which the oil is subjected, the oil being discharged from the burner or atomizer tip in the'form of a very fine spray.

For the purpose of illustrating my invention, I have shown in the accompanying drawings one form thereofwhich is at present preferredby me, in carrying out my novel method, since the same has been found in practice to give satisfactory and reliable results.

Figure 1 represents a side elevation or diagrammatic view partly insectionof one form of an apparatus adapted to carry out my novel method of atomizing-hydrocarbon fuel. Fig. Q represents on an enlarged 'scale a sectional elevation of a liquid atomizer wherein the atomizing steps of my process are carried out. Fig. 3 represents a sectional elevation of the tip for the same. Fig. 4 represents asectional elevation of the atomizer disk in detached posit-ion. Fig. 5 represents an end elevation of the atomizer disk.

Similar numerals of reference indicate corresponding parts in the figures.

Referring to the drawings :1 designates a furnace of any conventional or desired Patented Mar. 11, 1913.

type, which may be a stationary, marine, or locomotive boiler, and in the present instance, for purposes of illustration, I have shown my invention applied to a well known Scotch boiler, said furnace being provided with a combustion chamber 2, having a wall 3 preferably provided with a restricted inlet passage 4 forming a mixing or commingling chamber, between which and the furnace front 9 is located a receiving or air preheating chamber 5, which is preferably of greater area than the commingling chamber 4. i

7 designates a damper which is pivoted at 8 to the furnace front 9, and controls ad mission of air through theair inlet 10 to the chamber 5. The damper or door 7 may be controlled in any desired manner, either manually or automatically, depending upon the requirements and conditions met with in practice, and if the same is automatically controlled, any conventional or desired type of controlling mechanism maybe employed.

11 designates a thimble or sleeve which passes through and is secured in the front wall of the furnace, and is provided with the flange 12 contacting with the front 9.

13 designates a pipe or sleeve which is preferably slidably mounted within the thimble or sleeve 11, and at its forward .end, it is provided with a spider 14 which is secured to a cone-shaped damper 15,, the sleeve 13 being provided with an operating handle 16, whereby the cone may be longitudinally adjusted relatively to the burner or fuel atomizer 17, which latter is removably mounted on an oil conduit 18, extending through the sleeve 13.

The fuel atomizer, in the present instance, comprises a body portion or holder 19 having an internal bore 20, the outer end of which is preferably flared outwardly or beveled or inclined as indicated at 21. The end of the holder 19 is exteriorly threaded as at 22, thereby adapting the same to receive a clamping nut 23, which latter is provided with an inwardly projecting flange 24.

25 designates an atomizer disk which is provided with a rearward extension- 26, having preferably as in the present instance, a cylindrical contour, adapted to serve as a spreader or deflector, and which, when the parts are in assembled position, is adapted to extend into the bore 20 a desired distance. The disk 25 is provided with a laterally extending flange 27, which is provided with one or more ports or apertures 28, it being understood that the inner face of the flange 27 is adapted to seat against the end of the holder 19, which is facedofi' as indicated at 29. The front face of the disk 25 is provided with an extension 30 in the shape of a cone, for a purpose presently to be described.

31 designates one or more ports or passages, which extend tangentially from the apertures. 28 to the cone 30, the base of said cone having an annular groove 32, which extends slightly into the front face of the flange 27, as best seen in Fig. 4.

33 designates a tip which is provided at its rear end with a laterally extending flange-34 which is adapted to close the front end of the apertures or ports 28, when the parts are in assembled position, the forward end of the tip 33 being adapted to pass through the flange 24 of the. clamping nut 23. The tip 33 has an internal conical recess 35, which communicates with a re stricted outlet or discharge port 36 extending through the'forward end of the tip. The walls 37 of the conical recess 35, are angularly inclined to the walls of the restricted outlet 36, which is in practice about the size of a pin hole. In order to assemble the parts, the atomizer disk 25 is placed against the end of the holder 19, the tip 33 is then placed upon the disk 25, and theclamping nut 23 is secured in position, so that the shoulder 38, formed by the flange 24 of said clamping nut 23, will engage the flange 34 of the tip 33 and thereby cause the tip 33. and the atomizer disk 25 to be readily and effectively secured in assembled position with respect to the holder 19.

The hydrocarbon is forced into the supply pipe 18, and initially heated to the desired point by being pumped from the suction inlet 50 by the pump 49, through the outlet pipe 48 into the steam super-heating device 41, the latter having the heating pipes or loops 40, depending therein from the tube sheet 45.

The heating medium employed is preferably steam, as theexhaust from the pump 49 1 5 n or other source, whichmay be conducted into the pipe 43 to the compartments 51, which are separated by the partitions 52, one leg of each loop 40 communicating with each compartment so that the beating medium passes successively down and up each loop until it -enters the last compartment 46, and escapes through the outlet pipe 44. The plate 47 extends nearly to the base of the casing 41 and causes the hydrocarbon to be retarded in its passage through the heating chamber, said hydrocarbon after being heated to the desired degree, which is preferably somewhat higher than its normal boiling point, but not sufficiently high to be vaporized, being conducted frolnthe superheater by the pipe 39 to the pipe 18, the valve 42 controlling the supply of hydrocarbon as evident.

It will thus be seen that my novel method of atomizing and feeding hydrocarbon consists in forcing the hydrocarbon under pressure through a superheating chamber, and then conducting the heated hydrocarbon under pressure to the atomizing device,

wherein the novel steps hereinabove de-' scribed are carried out. While I preferably heat the hydrocarbon to a point higher than its normal boiling point, but not sufliciently a common right to initially heat the hydrocarbon unmixed with air or other gases to a point higher or lower than its normal boiling point or lower than that point at which vapors are generated under the pressure to which the oil is subjected and to maintain the oil in a liquid state by pressure while so heated and until delivered to the combustion chamber thereafter forcing the heated oil or hydrocarbon into a combustion chamber supplied with air, said hydrocarbon being unmixed with air or other gases, as stated, during said heating treatment, as shown in the British patent to Terry #18,443 of 1894, or British patent to Howden #12554, of 1899, and to the above steps per se I herein make no claim, as my present invention is primarily directed to the final atomizing steps, which may be effected either alone or in conjunction with the steps of the preliminary heatingof the hydrocarbon, as above described;

In the operation of the atomizing device during the carrying out of myvarious novel. atomizing steps, it will be apparent from Fig. 2, the incoming heated hydrocarbon is first deflected laterally by its contact with the spreader device 26, and then travels longitudinally through the ports 28 until it impacts against the flange 34. The movement of the fluid is then abruptly arrested and said fluid is then caused to travel inwardly at substantially a right angle through-the.

passages 31, and after its impingement on the walls of said passages,-t-he hydrocarbon is deflected tangentially against the wall of the gone 30 and its molecules given a rotary or swirling movement in the form of a thin conical film within the common, conical or other shaped commingling chamber formed between the cone 30 and the wall 37 of the tip 33. The outward movement of the hydrocarbon is momentarily checked by the restricted pin hole outlet 36, so that the finely divided molecules of the heated'hydrocarbon under pressure finally issue through the port 36 in the form of a fine spray, as is evident. I am aware that it is a common right to force a hydrocarbon under pressure un mixed with air or other gases to a reservoir, wherein the hydrocarbon is superheated to the desired point, whereby the oil may be heated to:a point lying higher than that at which under-atmospheric pressure, vapors would be developed, or its normal boiling point, but lower than that'point at which vapors are generated under the pressure the oil is subjected to, as in the patent to Solomin, No. 588,191, August 17th, 1897. I am also aware that it has been proposed to con vey heatedhydrocarbon under pressure to the combustion chamber of a furnace and to spray the same in to said furnace, commingling said spray with steam or air, as desired in patents to McDermot-t, No. 727,414 of May 5th, 1903, or Korting, No. 800,219, of Sept. 26th, 1905. My resent invention is however clearly di erentiated fromIIorting, since I employ in lieu of the usual construction of nozzle shown therein, my novel construction of atomizer, wherein my novel steps hereinbefore recited are carried out, and to none of the constructions of the prior art do I herein make any claim.

It will now be apparent that I have devised a novel and useful method of atomizing and feeding hydrocarbon to furnaces, wherein the hydrocarbon is preferably kept approximately at suitable predetermined degrees of temperature, under a desired pressure, and thereafter subjected to a series of .novel atomi'zing ste s, which so far as I am aware, are broad y new, and enables plants having apparatus therein wherein 'my novel method can be effected, to be op-' erated with great economy, since it is unnecessary to employ the injector action of steam 'or air to eflect the feeding of the hydrocarbon to the desired pointof combustion, and while'I have shown one preferred form of apparatus wherein the steps of my novel method may be carried out, it is evident that various other forms thereof may be devised bythose skilled in the art, without departing from the spirit of my invention.

Having thus described my invention, what 7 I claim asnew and desire to secure by Let-;

ters Patent, is

1. The method of firing furnaces, which 7 consists in heating hydrocarbon oil unmixed with air or other gases to a point higher than its normal "boiling point,.maintaining such heated oil in a liquid condition by pressure until its int-roduction'into the furnace, conducting the liquid toward the furnace in a single main line of flow, divertin the liquid into a stream or streams paral el to said main line of flow, conveying the stream or streams inwardly and tangentially to a circle having for its center the main line of flow, obstructing said inward and tangential stream or streams, spreading said-stream or streams into a thin conical film,;-whereby the film is contractediinto a jet, releasing the jet to form a diverging spray, and introducing diverging currents of air into the spray.

2. The method of firing furnaces, which consists in conducting th hydrocarbon fuel under ressure toward the furnace in a single main line of flow, diverting the hydrocarbon into a stream or streams, parallel to said main line of flow, conveying the stream or streams inwardly and tangentially to a circle having far its center the main line of flow, obstructing said inward and tangential stream or streams, spreading saidstream or streams into a thin conical film whereby the film is contracted into a jet, releasing the 10 jet to form a diverging spray, and introducing diverging currents of air into the spray.

KNUT M. DAHL. WVitnesses ARNOLD LESTER, THOMAS W000. 

